Strip Heaters Used for Severe Instrument Heat Tests

Chromalox catalog strip heaters

The Challenge
It was important for this aircraft manufacturer to provide heat tests for airplane altimeters to meet new Air Force requirements. Due to the very high altitudes and extremely varied temperature conditions met by ultrasonic aircraft, a heat test was deemed necessary. This required heating equipment that could hold the altimeters under test at temperatures of 45 degrees Centigrade for 2 or 3 hours.

The Solution
Design engineers designed and built a special glass enclosed oven equipped with three Chromalox strip heaters rated at 750 watts and 250 volts, with controls. The altimeters are placed inside the oven for heat testing to simulate varying conditions at altitudes up to 80,000 feet. Following the heating, the altimeters are adjusted and calibrated as needed for future service. Test operation was so successful, a second oven was built.


  • Accurate temperatures maintained for precision testing.
  • Equipment is efficient, clean operating without fumes or dirt.
  • Heaters and controls were easy to install.
  • Testing ovens were inexpensive to build.
  • Operating cost is low.